The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Is Dizziness A Side Effect Of Mounjaro?
Yes, dizziness can occur as a side effect of Mounjaro (tirzepatide), though it affects only a minority of people using this prescription weight management injection. Dizziness is listed as a common side effect in UK clinical data and patient reports. This guide explains what you need to know about dizziness on Mounjaro, how it relates to UK access routes (NHS and private), and the cost considerations for both pathways.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Dizziness on Mounjaro: What the Evidence Shows
Dizziness is classified as a common side effect of Mounjaro, meaning it may affect up to 1 in 10 people using the medication. In the SURMOUNT clinical trials, dizziness was reported during treatment with tirzepatide (the active ingredient in Mounjaro), though it was not among the most frequently reported side effects. Nausea, diarrhoea, and vomiting occur more commonly than dizziness.
Dizziness on Mounjaro may occur for several reasons: rapid blood sugar changes, dehydration from gastrointestinal side effects like diarrhoea or vomiting, dose escalation (Mounjaro uses a gradual titration schedule from 2.5 mg to 15 mg), or individual sensitivity. Most reports of dizziness are mild to moderate and tend to improve as the body adjusts to the medication over the first few weeks of treatment.
If you experience persistent or severe dizziness while taking Mounjaro, contact your GP or prescriber immediately — this is important information for your healthcare team.
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Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
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Accessing Mounjaro in the UK: NHS vs Private Route & Cost
NHS access: Mounjaro is available through specialist tier 3 weight management services following NICE approval, but availability varies significantly by region. Your GP refers you to a specialist service, which can involve lengthy waiting lists. Once prescribed on the NHS, you pay nothing at the point of use (standard NHS prescription charge applies).
Private access: You can obtain a Mounjaro prescription through a UK-licensed online prescriber without NHS referral. After a clinical assessment, a prescription is issued and dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 per month depending on your dose. Starting doses (2.5 mg) cost less; higher maintenance doses (10–15 mg) cost more. Compare with Wegovy, which has different pricing at different dose levels. Private prescriptions are processed within days rather than months.
Whichever route you choose, dizziness should be reported to your prescriber. Our free GLP-1 weight loss calculator can help you understand what to expect from tirzepatide treatment at different doses, and our BMI calculator will show you where you stand against NHS eligibility thresholds for weight management treatment. Both tools are available above to help you prepare for a consultation.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Is dizziness common on Mounjaro?
Dizziness is a common side effect, affecting up to 1 in 10 people using Mounjaro. However, it is less frequent than nausea or diarrhoea. Most cases are mild and tend to improve within the first few weeks as your body adjusts to the medication.
What causes dizziness on Mounjaro?
Dizziness on tirzepatide can result from blood sugar fluctuations, dehydration from gastrointestinal side effects, dose escalation during the titration schedule, or individual sensitivity to the medication. Staying hydrated and eating small, regular meals may help.
How do I access Mounjaro on the NHS in the UK?
Ask your GP for a referral to a tier 3 specialist weight management service. NICE has approved tirzepatide for NHS use, but availability varies by region and waiting times can be long. Eligibility requires a BMI of 30+ or 27+ with weight-related health conditions.
How much does Mounjaro cost privately in the UK?
Private Mounjaro typically costs £129–£320 per month depending on your dose and the provider. Starting doses cost less; higher maintenance doses (10–15 mg) cost more. Costs are charged per prescription after an online clinical assessment.
Should I stop Mounjaro if I experience dizziness?
Do not stop Mounjaro without speaking to your prescriber. Contact your GP or the healthcare professional who prescribed it immediately if dizziness is severe, persistent, or accompanied by other concerning symptoms. They may adjust your dose or investigate the cause.
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